Heat pump temperature settings for radatiors

hello

we have a system 12 black thermodynamics panels, 1 heat pump and 11 radatiors what's the best temperature setting for heat pump outdoor temperature is 8 degrees three days the system runs perfect then a error code comes up we have check water all ok, gas pressure is perfect can anyone help

Depending on the radiator sizing the required temperature can be from 35°C to 50°C.

You haven't said what the error code is or what make the system is so can't really help too much, sorry.

The make is the energypanel model is Gtc 12 and the code is aes